Chisato Asahi

Regional Vulnerability of the Tokyo Metropolitan Area to Flood and Earthquake Disasters

Until the 1970s, the majority of flood disasters occurred in the lowlands to the east of Tokyo. In recent years, however, with the increasing frequency of localized torrential downpours – referred to as ‘guerrilla rainstorms’ – locally concentrated, devastating damages have been suffered. With respect to measures against such damages, underground reservoirs and rivers are being constructed. As a soft measure, flooding hazard maps are being made public. Because of its densely concentrated urban structure, the Tokyo Metropolitan Area is also at high risk of fires and building collapses during earthquakes. Furthermore, a large-scale earthquake is expected to occur there in the near future. As mitigation measures, earthquake-proof reinforcement is being subsidized and disaster prevention activities and education are being conducted by community organizations. Although a variety of disaster prevention measures against floods and earthquakes are being conducted in the Tokyo Metropolitan Area, lowland areas could still suffer serious damage due to their densely concentrated urban structure. Since disasters affect society as a whole, vulnerability can be defined not only by such urban structure and mitigation measures, but also by the pre-disaster welfare state of individual households, capacity of administrative bodies and cooperation within them. Thus, we should clarify the respective roles of affected individuals, areas, and administrative bodies so that they complement each other. However, even administrative responses to disasters (rescue and assistance) have limits. Therefore, individuals should be prepared to protect their own lives and assets (self-help) and respond cooperatively in collaboration with their neighbours.

Sustainability and Human Well-Being

Subsequent to the publication of Brundtland’s report on sustainable development, the number of books and papers which include the words ‘sustainable’ in their title has grown enormously. However, the very elasticity of the concept has given rise to questions about what it is supposed to mean: the sustainability of what, for whom, for how long, and why? First, the concept of well-being is defined as a multi-level structure in this book. The first level of well-being consists of the sustainability of people’s basic living conditions such as income, health and so on. When we consider the improvement of people’s well-being, we should give precedence to securing the first level of well-being. Second, the equity problem is considered in the framework of welfare economics theory. Multiple criteria analysis is considered to be a promising method which takes into account not only both efficiency and equity but also many non-monetary items which constitute well-being. Concepts in sustainability and vulnerability are complementary and closely related; mitigating the vulnerability of the human-environment system can increase its resilience or sustainability. Vulnerability is not only an issue for developing countries such as Bangladesh, which is one of the poorest nations, but is also an issue for developed countries such as Japan.

A Supply System for Municipal Water with Uncertainties

In this chapter, the system of the provision of municipal water through the market mechanism including some forms of “privatizations” is considered in the view of the normative aspects of resource allocation and welfare under the uncertainty of water quality. First, the first and second fundamental theorems of welfare economics are reviewed and the cases that the market mechanism fails to satisfy the optimal allocation are shown. Second, among those cases, the problems relevant to the municipal water supply under the presence of environmental risk and asymmetric information between water supplier and regional consumer are considered. We review the analytical framework of credence goods and show the advantages of using it when the uncertainty of the water quality is at issue. Third, we assume that some private firms have chance to contract to provide municipal water and examine how the credence of municipal water, that means quality regulation, effects on the price and water quality level using an analytical model. A regulator of municipal water provision should control municipal water supplier by means of some kind of penalties and inspections, which work on the risk attitudes of the supplier and the probabilities of detection under informational asymmetry.

Economic Valuation for Improving Supply Reliability: Risk Countermeasures for Water Quantity and Quality in Water Supply Systems

In the supply of water, there is simultaneously a demand for maintenance of supply reliability from the viewpoint of public interest and a demand for efficiency against the backdrop of funding difficulty. In order to examine how these demands can be met through the use of market mechanisms and to identify the optimum replacement investment, maintenance and management, etc. for facilities, a framework must be created that ties together the risks of quantity and quality related to the reliability of supply with decisions concerning investment and the establishment of standards. This chapter uses an economic viewpoint to organize the risks of quantity and quality in and to utility water systems to conduct a valuation of countermeasures for these risks. The first two sections organize the changing nature and methods of understanding the water supply system for utility water and its quantitative and qualitative risks. Next section presents and considers establishment and operation cases of quantitative and qualitative risk countermeasures in current supply systems. Section 9.4 presents the optimization model for evaluating reliability to enable valuation of the supply system under these risks. The welfare measures that should be applied to risk-averse economic agents are organized based on welfare economics theory. The chapter concludes by summarizing critical system design focus points in order to realize a water supply system that is quantitatively and qualitatively reliable and efficient.

Evaluation of the Vulnerability of Municipal Water Infrastructure

In this chapter, we examine the welfare effects and their measurement of social overhead capital on a household. In Japan, the decline of population and the structural straits of public finance give rise to difficulties in maintenance and replacement of social overhead capital that have been invested through the period of high economic growth and the following period of the fiscal stimulus over 1990s. The importance of the basic service provided by the infrastructure service, such as public utility service or flood control, is however increasing because of transformation of regional structure caused by population decrease and continually concern for disaster. In order to solve the trade-off between the capacity limit of new public investment and the increasing needs for safety of life provided by social overhead capital, we show a model of welfare evaluation of vulnerability handled by the infrastructure and examine it in case of municipal water supply. First, we show the welfare evaluation model for vulnerability that household face. Second, the welfare measurement of vulnerability is developed especially in the view of theoretically appropriateness of welfare measurement. Third, preliminary inspections show the validity of the application of the model and some required conditions for evaluation.

Public investment for the risk management of municipal water: Evaluation and decision making

Water contamination risk has become more complicated and more uncertain. The difficulty of specifying the causality between water contamination and its sources makes it hard for the water service authorities to manage the risk; where the safety level of water quality should be set and how much should be spent for the risk reduction. Our paper focuses on the public decision-making on the risk management investment for municipal water quality by combining the economic evaluation method for risk and the research on the risk perception about municipal water. The authors present a model of economic evaluation of risk and lay out its extensive expression to evaluate a project. They consider the relation between risk perception and the estimate. Using questionnaires, they survey the risk perception of drinking water to evaluate the high water purification system investment.